Belzona Weatherproofing Solutions to Roof Problem Areas

by admin

Roofs commonly suffer from damage caused by movement during freeze-thaw cycles, physical damage, rain and adverse weather conditions. Flat roofs in particular can deteriorate quickly due to standing rainwater, which in turn leads to leaks at the joints and seams, flashings, gutters or glazing bars.

Replacement can be very costly, conventional roof repairs do not offer long-term protection and involve either hot work, which is unsafe and disruptive, or the use of hazardous solvent-based materials. Ignoring the problem is not an option. Deteriorating roofs can compromise the building’s structural integrity, restoration of which will be a time consuming, costly exercise.

Belzona offers a cost effective solution to various roof problem areas that can be easily applied to numerous substrates, such as asphalt, felt, lead, glass, stonework and aluminium amongst others. Belzona 3111 (Flexible Membrane) System is a liquid applied single component, solvent free, microporous coating for the long term repair and protection of all types of roofs.

Once cured it remains flexible in service allowing roof structure to move but remain water-tight. (The system will have 100% crosswise and 20% lengthwise elongation – BS2782 test.) This versatile material provides outstanding weather proofing and waterproofing properties with excellent protection against ultra violet radiation and lends itself to application onto complex contours.

European Technical Approval ETA-05/0075 states that the expected economically reasonable working life of Belzona 3111 (Flexible Membrane) roofing system is 25 years. The certificate was issued by the British Board of Agrément and is available to view online through their database.  View the certificate here.

Belzona 3111 (Flexible Membrane) is a proven weatherproofing solution with known applications in service for over 25 years. In Cilfynydd, South Wales in 1988 a roof project was completed by applying a Belzona high performance, liquid applied membrane system to a flat roof. When inspected 25 years later the membrane system has remarkably withstood all climatic and movement conditions and has provided full barrier protection despite a quarter of a century of British weather.

[Weathered but watertight after 25 years]

Excellent adhesion ensures no peel-back of the edges making Belzona ideal for localised repair, where corner leaks can be promptly eliminated. In 2008 one corner of a roof on a Military base in the US was repaired in one day and the roof was leak free the following morning when a storm came in. For further information on this application, view our case study here.

Belzona 3111 (Flexible Membrane) is a coating that is brush applied in conjunction with Belzona 9311 (Reinforcement Sheet), which enables it to encapsulate many complex contours or substrates. In 1974, a deteriorating papier-mâché dome of the UK observatory needed urgent attention. A fully reinforced Belzona system was used to fully encapsulate the dome. To ensure complete weatherproofing for future years a single layer of Belzona 3111 (Flexible Membrane) was subsequently applied in 1988. This application was recently inspected and still found to be in perfect condition. For further information on this application, view our case study here.

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[Original application in 1974]                [Revisited in 2010, still in perfect condition]

Difficult contours, where other repair attempts have failed are not a problem for Belzona. In 2007 NASA hangar’ skylights were leaking and several earlier attempts to seal them proved futile. Utilising cold applied Belzona 3111 (Flexible Membrane) system all 16 skylights were sealed and leaks eliminated, not compromising on the appearance of the roof. For further information on this application, view our case study here.

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[Leaking skylight]                                                                 [Completed Belzona application]

Belzona is not just a product manufacturer but strives to provide a complete supply and apply package through its Global Distribution network specifically created to provide clients with direct access to Belzona quality products, specialist application services, inspection services and supervision. It is Belzona’s mission to meet specialist repair and maintenance needs in its target industries and markets worldwide.

To weatherproof your roof for the long term, contact Marina Silva on 01423 567641, or visit

Applications mentioned in this article along with other case studies, recounting Belzona success stories in roof weatherproofing and more, are available to view at

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